Drugs, pharmaceuticals or medicaments can be orally administered in the form of powders, dropping solutions or juices. However, as the precise dosage is difficult to determine using these forms for administering drugs, manufacturers generally give preference to dosage forms, such as tablets, dragees or capsules. Reagents and other active agents, e.g. sweeteners are frequently tabletted for precise dosage use. Although methods for the production of tablets, dragees, capsules and the like have been developed to a very advanced degree, it is impossible to overlook a number of problems associated with these dosage forms.
When low doses of active agents are to be administered a considerable amount of adjuvant must be present in order that the preparation given is of a manageable size. Further, since it is virtually impossible to accurately mark individual tablets or dragees, blister packs containing a large number of tablets, dragees and capsules, have become widely used and are printed with the necessary information, such as the name of the product. However, the production of such packs requires an additional operation. In addition, the packs require further packaging in the form of folding boxes which have a considerable empty volume and therefore take up additional storage space.
A particular disadvantage associated with dragees and capsules is that it is virtually impossible to split them, so that the smallest dose must always be predetermined. Even in the case of tablets, only larger tablets with a notch or groove at the predetermined breaking point can be divided or split, but this often results in fragments of unequal size.
Attempts have been made to provide a new dosage form for orally administered drugs that is, active agent-containing films. Belgian Patent No. 637,363 discloses a paper-like carrier material of insoluble cellulose fibers, impregnated or coated with an active agent solution. The carrier film is perforated, in the manner of a sheet of postage stamps, in order to provide individual doses. German Patent Nos. DE-OS 24 32 925 and DE-OS 24 49 865 disclose incorporating drug active agents into film formers, preferably comprising water-soluble compounds, such as methyl and ethyl cellulose. Hydroxypropyl cellulose, hydroxyethyl cellulose and methyl hydroxypropyl cellulose can also be used. The thus obtained active agent-containing film can also be subdivided by perforation into individual portions for dosage purposes.
These proposals have not been used in practice and no mention is made thereof in "Arzneiformenlehre" by P. H. List, 4th edition, Stuttgart, 1985. This is due to the fact that the necessary weight constancy and uniform active agent distribution have not been achieved.
For example, Ph. Eur., fixes criteria for weight uniformity of individually dosed medicaments, in which the latter are graduated in accordance with the particular average weight on the basis of maximum admissible divergences in %, that is .+-.5 to 10%. There are also corresponding values for solid medicaments relating to other parameters, such as the disintegration time and rate of dissolution.
The aforementioned proposals result in products which are difficult to ingest and are inconsistent as to dosage per surface unit. Further, when incorporating an active agent into a film, not only does the problem of precise dosage occur, but a corresponding film must be produced separately for each active agent. Thus, the production process is not advantageous from an economical standpoint.